Use COUNTIF() in the conditional format. Say your data is from A1 thru Z50.

Select A1 and set the conditional format t:

Formula Is:
=COUNTIF($A$1:$Z$50,A1)1 and pick a distinctive format

Copy A1 and pastespecial / formats from A1 thru Z50
--
Gary''s Student - gsnu200753


"Mac" wrote:

I have like 300 columns with 50 values in each and I want to find duplicates
accross these groups - e.g. number 23,5366 appears in group no. 23, in group
no. 45, in group no. 145 twice, etc. - and I needto get back the row
reference of these duplicates ( conditional highlighitng would sufice). How
can I achieve this?